Answer:
The answer to your question is r = 3
Explanation:
2r - 15 = - 9r + 18
Process
1.- Add 9r in both sides
2r + 9r - 15 = - 9r + 18 + 9r
2.- Simplify
11r -15 = 18
3.- Add 15 to both sides
11r - 15 + 15 = 18 + 15
4.- Simplify
11r = 33
5.- Divide both sides by 11
11/11 r = 33/11
6.- Simplify and result
r = 3